Lens-blocking device



Sept. 10, 1929. MCCAB 'E mus YBLOCKIIZIVG DEVICE Filed June 2. 1927 4Sheets-Sheet 1 HIHIHI p 10, 1929- J. J. M C'AB E 1,727,889

LENS BLOCKING DEVICE Filed June 1927 4 Sheets-Sheet 2 4 v I n PatentedSept. 12, 1229.

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JOSEPH J". IMCCABE, OF ROCHESTER, NEWYORK', AS$IGNOR TO BAUSCH &. LOMBOPTI- CAL COMPANY, OF ROCHESTER, NE't/V'YORK, A CORPORATION OF NEW YORK.

LENS-BLGCKING DEVICE.

a device ofv the above nature which is of simple and durableconstruction and by means of which lens blanks may be quickly 'andaccurately positioned on blocking bod ies. Another object is to providea device by means of which a lens blank which is. to be ground. toprovide a lens with prisnrmay be so positioned ona. blocking body thatthe baseof the prism may be accurately located in any desired meridan.Another object is to provide a device by means of which alens blank maybe so positioned on a blocking body that the cylinder axis of thetinished lens may be located in any desired meridan. Other objects will.be-in part obvious or in part pointed out hereinafter.

The invention accordingly consists in the features of construction,combinations of elen'ients, and arrangements of parts as will beexemplifiedin the structure to be herein: after described and the scopeof the applies; tion of which will be indicated in the following claims.

In the accompanying drawings in which is shown one of the variouspossible embodiments of thisinvention,

Figure l is front elevation" of thensembled device;

Figure 2 is a side elevation of the assembled device;

Figure 3 is a sectional side elevation taken substantially through thecenter of Figure 2 and showing the table member rotated through ninetydegrees;

Figure l is a plan view of the assembled device;

Figure s a view taken substantially on line 55 of Figure 3;

Application filed June 2, 1 927. Serial No. 198,112.

Figure'6 is a plate;

Figure 7 is a view showing the effect of the grinding operation on thelens shown in F igure 3; I

Figure 8 is a: fragmentary plan View of the device with the lens'retaining means and lens block removed and. showing the lens blockadapter;

Figure 9 is a sectional plan view taken immediately above thetablemember; and Figure. 10 is a perspective view of the ro-. tatable supportfor the table member.

Similar reference characters refer to similar parts throughout theseveral views of the drawings. I

Referring now to the drawings in detail, there is shown a base having asubstantially cylindrical supporting member 21 detachably mountedthereon. A vertically bored lug 22 may be integrally formed with orrigidly mounted upon the upper surface of the base 20 substantiallycentrally thereof. A rod or plunger 23 having an adapter 2st rigidlymounted on anend portion there of is mounted for vertical slidingmovement within the opening in the. member 22. A key 25 locks the rod 23against rotation.

The rod 23 also extends through centrally disposed openings in the guidemembers 26 and 27 which are detachably connected by means of the screws30. The guide members 26 and 27 are rotatable-as a unit relatively tothe rod 23. adapter 2+1, and supporting member 21 and'have surfacesengaging the inner, upper and. lower surfaces of an annular shoulder 31formed on the upper portion of the supporting member 21.

-Four lens supporting pins 32 of equal lengths and provided with taperedend portions extend through openings in the mernplan view of the indexbers 26 and 27 to points above and below said members. Each pin 32 isprovided with a collar 33 which is adapted for. contact with the uppersurface of the member 27 to limit the downward movement of said pin. Ahclical spring 34. is mounted on each pin between the collar 33 and the.lower surface of the member 26.

The rod 23 carrying the lens block adapter.

2st may be moved upwardly, tor a purpose to be later described, throughthe agency of a pivoted lever 35 which is supported by a lug formed onthe supporting member 9.1.

The inner end portion of the lever 35 is provided with a rounded uppersurface with which the lower rounded end of the rod 23 is normally incontact.

The lower end portions of the lens supporting pins 32 are normally incontact with the upper surface of a pivoted table member 36 carried bythe substantially cylindrical supporting member 37. provided withtapered end portions, extend through openings in opposite sides ot themember 37 and have their tapered ends eX- tending into recesses formed..in pins ll mounted on opposite sides of the table mem her. Set screws12 permit adjustment of the pins it). An adjusting arm d3 may be rigidlymounted on or formed integrally with the table member. The adjusting arm48 e2;- tends from the interior to the exterior of the device throughslots formed in the Walls of the members 21 and 37.

The slot formed in the member 37 is substantially L-shaped to permitvertical movement of the adjusting arm l3 and rotational movement of themember 37 relatively to the pivoted lever The slot in the member 21 isso formed that the lever 35 and bracket 44 may extend therethroue h andit is of sullicient length that the bracket 44 may move throughsubstantially 180 degrees.

The bracketl i is mounted on the outer wall of the member 37 adjace itthe adjusting arm l3 and provided with an arcuate substantiallyvertically extending slot l? through which a locking screw 46 is adaptedto extend. The threaded end portion of the locking screw d6 is adaptedto iit within a threaded opening in the outer end portion of theadjusting arm The locking screw 46 may be manipulated to lock the arm 13in contact with the bracket M. An index plate e 8 is pr Med with acentral opening and arcnate grooves for the reception of the lenssupporting pins. The index plate rests upon the upper surface of themember 26 and may he moved vertically.

In attaching a lens blank to a lens blocking); body. a. blocking body 47such as thatshown in Figures 3 and 7 is provide-don its upper surfacewith a ringr layer of pitch or other adhesive substai'ice and mounted onthe adapter Ql. The adapter is provided with a rigidly mounted pin 50which cerrcsponds to a. pin carried by the lens block supporting bracketoi the lcns g;rin= ing machine, and the lens block is provided with aslotor recess for receiving the said pin Set screws 51 are provided forlocking the blocking body in position in the adapter. The adapter andits supporting rod may be removed from the device for the purpose P inmembers 40.

of positioning and removing the lens blockmg body, grooves beingprovided 1n the -members 26 and 2' to permit the key 25 to ,be drawntherethrough.

After the lens block has been placed in position the adapter, rod andlens block are placed in the device and the adapter and lens block willoccupy the positions shown in Figure 2. A lens blank may-then be mountedon the upper end portions oi the lens supporting pins and clamped inposition by means of the pressure pins 52.

The pressure pins 52 are mounted on a yoke 53 which is pivotally mountedon a boss 5% formed on an end of a supporting arm 55 which is mountedfor sliding movement on the vertical post 56. The post 56 is carried bya lug 57 termed on the sup porting member 21. A key 60 locks the arm 55against rotational movement and a locking screw 61 is provided forlocking the said arm against vertical movement. A helical spring 62 hasits end anchored at 63 and 64 on the supporting arm and lug 57 and tendsto draw the supporting arm downwardly when the. locking member 61 isreleased.

A sight tube 65 extends through an open-' ing in the box 54 and it is sopositioned that its vertical axis lies in the vertical axis of the lensblock, adapter, and supportinp; rod A. set screw 66 provided for lockingthe sight tube in position.

The lens blank should be provided with a center mark and an axis linerelatively to which the cylinder axis is to be located before being;placed in position on the lens supportingpins. If it is desired toproduce a finished lens having an edge of uniform thickness the lenssupporting pins should all be adjusted to the same height. This is doneby adjusting the table member until its upper surface is level. If it isdesired to make a lens with a prism, the table member is rocked untilits upper surface forms the proper angle with the horizontal. In thismanner the relative heights of the lens supporting pins are changed theproper amount, elevating one side portion of the lens blank and loweringthe oppositei portion.

For aiding; in determining the angular position of the top of the tablemember relatively to the horizontal and thus dc tcrminiiug the relativepositions of the lens su porting pin members. a scale 0 is inscribed.upon the fixed bracket all and a cooperating vernicr 71 is inscribedupon the outer end of the movable adjusting: arm

Then the lens supporting pins through the agency of the table member andadjusting arm. have moved to their proper positions. the table memberlocked in po sition by m ans at the screw -31) and the supporting member37 carrying the table IOU liZU

member and the fixed bracket 44 may be rotated relatively to the adapterand the pin sufficiently to place the base of the prism in the desiredmeridian. For aiding in determining the angular displacement of theprism base relatively to the pin 50, scale 72 and the cooperating indexmember 73 are provided.

In attaching the lens blank to the block by means of the device of thisapplication the blank is positioned relatively to the longitudinal axisof the pin 50. In the machine of my copending application mentionedabove the longitudinal axes of the pin which corresponds to the pin 50lies in a horizontal plane containing one of the principal meridians ofa lens immediately after the grinding operation and before the removalof the lens and lens block from the machine. Accordingly, in fixing oradjusting the positions of the axisline and the prism base relatively tothe axis of the pin 50, their positions relatively to the cylinder axisof the finished lens are also fixed.

To place the axis line of the lens blank in the proper angular positionrelatively to the pin 50, the members 26 and 27 carrying the lenssupporting pins and index plate 4.8 are rotated about the adapterthrough the desired angle as indicated by the gradiiated scale 74 on themember 26 and the index line 75. The screw 76 extending through the wallof the member 31 and into contact with the member 27 may be nianipulatedfor locking the members 26 and 27, the index plate and lens supportingpins in their proper angular positions.

\Vhen the proper adjustments of the various parts of the device havebeen made the lens blank is shifted to such a position that the markedcenter comes directly under the aperture in the sight tube and the axisline inscribed thereon coincides with the axis line on the index plate48.

After the lens blank has been properly positioned the arm 55 carryingthe pressure pins 52 is locked in position by means of the screw 61. Thelens blocking body is then heated by gas flame or other means until thepitch is softened. after which the blocking body is moved intoengagement with the lower surface of the lens blank by downward pressureon the l ver arm 35.-.--'A weight 77 mounted on the lever 35 issufliciently heavy to press the blocking body gently against the lensblank. A. locking screw 80 extending through a slot in a bracket 81carried by the base 20 and entering a threaded opening in the lever arm35 may be manipulated to lock the lever 35 in position. The lever arm 35is prcferablv not locked in position while the pitch is cooling, as incooling the pitch contracts and if the lever arm were locked againstmovement, an objectionable strainbetween transferred to the generatingmachine.

From the foregoing it will be seen that vthere is herein provided adevice which embodies the features of this invention and achieves theobjects thereof. A lens blocking device is provided which is of simpleand durable construction and by means of which a lens blank may bequickly attached to a blocking body in such a manner that it may bereadily transferred to a grinding or generating machine and ground toprovide a lens having the prism base and cylinder axis accuratelypositioned in the desired meridians.

As many possible embodiments may be made of this invention, and as manychanges might be made in the embodiment above set forth, it is to beunderstood that all matter hereinbefore set forth or shown in theaccompanying drawings is to be'interpreted as illustrative and not inalimiting sense. I claim as my invention: 1

1. In a lens blocking device, a support, a pivotally mounted tablemember thereon, lens supporting means mounted on and movable relative tosaid table member, and a lens block adapter for supporting a lens blockarranged to support a lens carried by said lens supporting means.

2. In a lens blocking device, a rotatable support, a table memberpivotally mounted on said support separate relatively movable, lenssupporting devices mounted on said table member, and a lens blockadapter for supporting a lens block arranged to support a lens carriedby said lens supporting devices. 1*

3. In a lens blocking device, a frame, a pivotally mounted table membermounted on said frame, lens supporting means slidable on said frame andengaging said table member, means for holding a lens in position on saidlens supporting means, and a lens block adapter for supporting a lensblockarranged to support the lens carri'ed by said lens supportingmeans.

4:. In a lens blocking device, a rotatable support, a table membertiltably mounted on said support. means for securing the table member indifferent tilted positions upon the support, lens supporting devicesmounted on said table member, resilient means for holding a lens inposition on said lens supporting devices, and a lens block adapter forsupporting a lens block arranged to support the lens carried by saidlens supporting means.

.5. In a lens blocking device. a lens block adapter vertically disposed.lens supporting members positioned on opposite sides of said adapter,guide means for said members, and means for simultaneously moving saidlens supporting members vertically and in opposite directions to adjustthe position, of av lens thereon.

6. In a lens blocking device, a lens block adapter, a lens block carriedthereby and arranged to support a lens blank, a rotatable support, atable member pivotally mounted on said support and arranged to be tiltedthereon to different angular positions, and upstanding pin memberspositioned on opposite sides of said adapter and engaging said tablemember at different points of elevation, the upper ends of said pinmembers forming a support for the lens blank.

7. In a' lens blocking device, an adjustably mounted lens block adapter,a rotatable support, a table member pivotally mounted on said support,lens supporting pin members positioned adjacent said adapter andengaging said table member, and resilient means for holding said pinmembers in engagement with said table member, the adapter being mountedin a position to be secured to a lens supported on said pins.

8. In a lens blocking device, an adjustably mounted lens block adapter,a support rotatable about the vertical axis of said adapter, a tablemember pivotally mounted on said support, vertically extending pinmembers engaging said table member and movable about the vertical axisof said adapter independently of said table memher.

9. In a lens blocking device, an adjustably mounted lens block adapter,a support rotatable about'the vertical axis of said adapter, a tablemember pivotally mounted on said support, a pluralityof lens supportingpin members mounted for rotation about the vertical axis of said adapterarranged to engage the table, and means for holding lens in position onsaid pin members.

10. In a lens blocking device. a base, a plurality of verticallydisposed relatively movable lens supporting elements arranged to engagea lens at different points, means movable upon the base to effectvertical movement of said elements one relative to another whereby toshift the lens to a. pro determined position. and means movable relativeto said elements arranged to support or hold the lens in said position.

lar position with respect to the horizontal and a lens block movablevertically to support the lens in the position to which it is moved bysaid elements.

12. In a lens blocking device, a base, a plurality of verticallydisposed relatively movable lens supporting elements arranged to engagea lens at different points, guide means for said elements, means movableupon the base to sinmltaneously effect vertical movement of saidelements where by to shift the lens to a predetermined angular positionwith respect to the horizontal, and relatively movable devices forengaging opposite sides of the lens to hold it in said position. 3

13. In a lens blocking device, a base, a plurality of verticallydisposed relatively movable lens supporting elements arranged to engagethe lens at different points, means movable upon the base to effectvertical movement of said elements one relative to another whereby toshift the lens to a predetermined position, means for rotating saidelen'ients to effect rotation of the lens, means above the lens forholding it in engagement with said elements, and means beneath the lensfor supporting it in said predetermined position.

I L. In a lens blocking device. a base, a plurality of relativelymovable devices forming means for supporting a lens in a substantiallyhorizontal position, one or more of which is adjustable to move the lensrelative to said position. rotary control means for said adjustabledevices adapted during rotation to move the latter whereby to shift thelens to said position, and relatively movable holding parts adjustableto engage the opposite sides of said lens when moved to said position.

15. In a lens blocking device, a base, a plurality of relatively movabledevices forming means for supporting a lens in substantia-lly horizontalposition, one or more of which is adjustable to move the lens relativeto said position, rotary control means for said adjustable devicesadapted during rotation to move the latter whereby to shift the lens tosaid position, relatively movable holding parts adj ustable to engagethe opposite sides of said lens when moved to said position, and a sighttube carried by one of said parts for viewing a mark on the lens wherebyto determine when the lens is in a predetermined position of adjust menton said devices.

16. In a lens blocking device, a base, relatively movable devices on thebase for supporting a lens in substantially horizontal position,operating means for moving one or more of said devices whereby to shiftand incline the lens with respect to the horizontal, a support carriedby the base, and a sight tube on the support for viewing a mark on thelens whereby to determine when the lens is in a predetermined positionof adjustment on said relatively movable devices.

17. In a lens blocking device, a base, lens supporting means carried bythe base for holding a lens in a predetermined position and includingparts certain of which are movable to shift the lens relative to saidposition, means for effecting movement of said parts and a lens blockmovable between said parts into position to support said lens.

18. In a lens blocking device, a base, a lens supporting blockadjustable thereon, relatively movable devices engaging the lens atdifferent points and adjustable to shift it to a predetermined positionfor subsequent support by the lens block, means for effecting movementof said devices to shift said lens to said position, 'and means formoving the lens block to support the lens in said position.

19. In a lens blocking device, lens supporting block adjustable upon thebase, relatively movable devices engaging the lens at different pointson the side nearest the block, means for simultaneously rotating andmoving said devices one relative to another to move the lens to apredetermined position, and means for moving the lens block to supportthe lens in said position.

20. In a lens blocking device, lens supporting block adjustable upon thebase, relatively movable devices engaging the lens at difi'erent pointson the side nearest the block, means for simultaneously rotating andmoving said devices one relative to another to move the lens to apredetermined position, means for moving the lens block to support thelens in said position, a. holding device supported by and mounted formovement relative to the base and including means arranged to engage andhold the lens upon said relatively movable devices, and a sight tubecarried by said holding.clevice for viewing a mark on the lens todetermine when the lens is adjusted to a predetermined position. j

21. In a lens blocking device, a base, a rotary support carried by thebase, a device tiltable upon the support to different-angua base, a

a base, a

lar positions, means for holding said device in said differentpositions, a plurality of lens supporting elements having their lowerends resting on said device, the upper ends of said elements beingadapted to receive a lens, guide means for said elements rotatablymounted to move the same whereby to shift the lens to a. predeterminedposition, and means movable relative to said elements arranged tocooperate therewith in holding the lens in said position.

22. In a lens blocking device, a base, a

member tiltably mounted Within the base, means for holding said memberin difierent adjusted positions, a plurality of lens supporting elementsresting on and projecting upwardly from said tiltable member andarranged to receive a lens on their upper ends, guide means throughwhich said elements are projected, said guide means being rotatable toeffect rotation of said elements whereby they are moved vertically onerelative to another to shift the lens to a predetermined position, saidguide means and said base having cooperating scale and index markingsfor indicating the extent of rotation of the guide means and said baseand tiltable member also having cooperating scale and index markings forindicat ing the angular relationship of the tiltable member relative tothe horizontal, means for exerting pressure on the lens to hold it inadjusted position upon said supporting elements, and a lens blockadjustable beneath the lens into supporting relationship With respectthereto.

JOSEPH J. MOCABE.

